Authorities do not believe the boy or the mother were targets in the shooting.

Police said the shooter fled north on Plainfield Avenue, then east on West Front Street.

The mother grabbed her son and transported him to the hospital, authorities said.

Investigators are pursuing several leads in the case, but Plainfield police, who are working with the Union County Prosecutor's Officer, are asking anyone with information about the shooting to call city police Detective Ivelisse Grimmer at (908) 413-3420 or the Union County TIPS Hotline at (908) 654-8477.